Read the contents of a file by providing its relative path. Use this to retrieve text or data from files for processing or analysis.
[MCP:fs] Read the contents of a file.
| Name | Required | Description | Default |
|---|---|---|---|
| path | Yes | File path relative to root |
Changes observed during successful MCP inspections.
v0.1.3Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden. It implies a read-only operation but says nothing about encoding, binary files, size limits, path resolution relative to root, or what happens on a missing file — all material for a filesystem read.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
One short, front-loaded sentence with no filler. It is appropriately sized, though its brevity comes partly at the cost of the missing behavioral detail noted elsewhere.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
A one-parameter read tool is simple enough that the definition is minimally viable, but with no output schema the description should at least indicate what is returned (raw text, error on binary) and confirm read-only safety, which it does not.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
The single parameter has 100% schema description coverage ("File path relative to root"), so the baseline is 3. The description adds no syntax, relative-path rules, or constraints beyond what the schema already states.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
States a specific verb and resource ("Read the contents of a file") with the "[MCP:fs]" namespace marker. An agent can distinguish it from fs__fs_list_directory by inference, but the description never names the sibling or contrasts the two explicitly.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
No guidance on when to use this versus fs__fs_list_directory or other fs tools, and no preconditions such as the file needing to exist or being text vs binary. The only cue is the implied "if you need contents, read".
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.